US7857508B2 - Method for monitoring the functionality of a temperature sensor - Google Patents
Method for monitoring the functionality of a temperature sensor Download PDFInfo
- Publication number
- US7857508B2 US7857508B2 US11/793,836 US79383605A US7857508B2 US 7857508 B2 US7857508 B2 US 7857508B2 US 79383605 A US79383605 A US 79383605A US 7857508 B2 US7857508 B2 US 7857508B2
- Authority
- US
- United States
- Prior art keywords
- sensor
- temperature
- cooling fluid
- time
- measured
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related, expires
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/22—Safety or indicating devices for abnormal conditions
- F02D41/222—Safety or indicating devices for abnormal conditions relating to the failure of sensors or parameter detection devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P11/00—Component parts, details, or accessories not provided for in, or of interest apart from, groups F01P1/00 - F01P9/00
- F01P11/14—Indicating devices; Other safety devices
- F01P11/16—Indicating devices; Other safety devices concerning coolant temperature
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P11/00—Component parts, details, or accessories not provided for in, or of interest apart from, groups F01P1/00 - F01P9/00
- F01P11/14—Indicating devices; Other safety devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P2031/00—Fail safe
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
- F01P2031/00—Fail safe
- F01P2031/30—Cooling after the engine is stopped
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Definitions
- the present invention relates to a method for monitoring the functionality of a temperature sensor.
- German Patent Publication No. DE 101 20 968 It is known from German Patent Publication No. DE 101 20 968 to check during operation whether a change in the cooling water temperature occurs upon a transition from a low to a high load range. If not, a fault is reported.
- German Patent Publication No. DE 44 26 494 discloses the monitoring of a cooling temperature sensor and of a thermostat by monitoring the change over time in the temperature sensor. If that change is too great, a fault is detected.
- the temperature behavior upon engine startup and under specific driving conditions, such as idling, is additionally checked, on the one hand based on typical rises in cooling temperature after engine startup, and on the other hand by means of a comparison with other signals.
- a method for monitoring the functionality of a temperature sensor that can deliver an electrical signal as a function of the measured temperature and is disposed, in particular, in the cooling water circuit of an internal combustion engine, encompassing the steps of: characterizing the sensor as possibly faulty if the sensor indicates, upon engine shutdown, at least a maximum value of the cooling fluid temperature; determining a first gradient of the cooling fluid temperature, measured by the possibly faulty sensor, up to a first point in time after engine shutdown, and characterizing the sensor as fault-free if the gradient exceeds a minimum value; determining a second gradient of the cooling fluid temperature, measured by the possibly faulty sensor, between the point in time and a point in time after engine shutdown, and characterizing the sensor as fault-free if the second gradient exceeds a minimum value; determining the cooling fluid temperature measured by the possibly faulty sensor at a point in time after engine shutdown, and characterizing the sensor as fault-free if the cooling fluid temperature falls below a maximum value.
- What is monitored is a sensor that assumes a higher value in normal operation than in the context of a cold start, and decreases back to an ambient value after engine shutdown. This is typically the case for temperature sensors, in particular in the context of cooling water temperature. Only the one sensor signal is evaluated for monitoring purposes; further comparison signals are not needed. A monitoring result is available after each driving cycle; specific operating conditions or long non-operating times need not be accommodated. It is not necessary to wait for complete cooling of the engine, which moreover would be difficult to detect or would require a clock to run in order to measure non-operating time. Monitoring occurs specifically to determine whether the sensor persists in a high signal range.
- the senor in a refinement of the method according to the present invention, provision is made for the sensor to be characterized as possibly faulty if it continuously indicates, prior to engine shutdown, at least the maximum value of the cooling fluid temperature. “Continuously” is understood here to mean a long period of time, e.g. several minutes.
- FIG. 1 shows examples of temperature profiles.
- FIG. 2 shows the temperature profile measured by the sensor after engine shutdown.
- FIG. 3 is a flow diagram of the method.
- FIG. 1 shows an example of possible signal profiles of a temperature sensor during operation of an internal combustion engine over time.
- the temperature T measured by a sensor is depicted, as a function of time t.
- the temperature sensor is one in the cooling fluid circuit of an internal combustion engine, which sensor converts the measured cooling fluid temperature into an electrical signal.
- FIGS. 1 and 2 depict the sensor signal as delivered and as converted into a temperature.
- a temperature T is referred to in the context of FIGS. 1 and 2 , what is therefore meant is the temperature measured by the sensor and indicated, not the real temperature actually present in the cooling circuit.
- the depictions in FIGS. 1 and 2 are therefore basically to be interpreted as the electrical output variables of the temperature sensor.
- FIG. 1 Four examples of temperature profiles over time are depicted in FIG. 1 .
- a maximum temperature Tmax is plotted as a horizontal dashed line.
- curves are depicted, characterized with numbers 1 , 2 , 3 , and 4 .
- Curve 1 proceeds continuously below the maximum temperature Tmax.
- Curve 2 proceeds largely below the maximum temperature Tmax, and exceeds the temperature Tmax shortly before a time t 1 that characterizes engine shutdown.
- Curve 3 continuously exceeds the maximum temperature except for a short period of time, and curve 4 continuously exceeds the maximum temperature.
- the time t 1 is engine shutdown, i.e. the internal combustion engine is switched off.
- the temperature sensor for the cooling fluid is also subjected to a plausibility test. Firstly a determination is made as to whether the sensor is possibly faulty. This determination can be performed according to two different criteria. On the one hand, the criterion employed can be whether the temperature measured by the sensor at engine shutdown t 1 is above the maximum temperature Tmax. If so, it is assumed that the sensor is possibly persisting in the high signal range, and is continuously measuring too high a temperature. In the examples of FIG. 1 , this would be the case for curves 2 , 3 , and 4 .
- FIG. 2 depicts the temperature profile measured by the sensor after engine shutdown.
- the respective temperatures T measured by the sensor are measured and are stored in a memory cell of, for example, the control unit.
- Temperature T 1 is associated with time t 1 , temperature T 2 with time t 2 , etc.
- What is depicted, as in FIG. 1 is the signal as a function of time that is furnished by the sensor and converted to a temperature value.
- the temperature measured by the sensor first rises briefly after engine shutdown; this behavior occurs, for example, because of the stored heat of the internal combustion engine.
- a temperature gradient ⁇ T 1 (T 2 2 ⁇ T 1 ) 1 /(t 2 ⁇ t 1 ) is therefore initially ascertained between engine shutdown t 1 and a first time t 2 located thereafter. If this gradient is above a positive minimum value, it is assumed that the sensor is fault-free.
- a second temperature gradient ⁇ t 2 (T 4 ⁇ T 3 )/(t 4 ⁇ t 3 ) is then ascertained. If the second temperature gradient ⁇ T 2 is above a negative minimum value, the sensor is classified as fault-free. Lastly, a determination is made as to whether at time t 4 , the temperature T 4 is below a maximum value defined for temperature T 4 . If so, the sensor is once again classified as fault-free.
- FIG. 3 shows the entire method as a flow diagram.
- the method begins at a step 1 upon engine startup. Until engine shutdown in step 2 , monitoring occurs continuously to determine whether the temperature T(t) is less than the temperature Tmax. If so, in a step 3 the sensor is classified as functional and fault-free. If not, the loop is cycled through again until the “Engine shutdown” condition in step 2 is met (Yes).
- a further checking step 4 checks whether at the moment of engine shutdown, temperature T(t) is less than the temperature Tmax. If so, execution once again branches to step 3 and thus to a fault-free sensor. If not, then in a step 6 firstly the engine post-operation phase is prolonged to at least the value t 4 ⁇ t 1 .
- step 3 the sensor is classified in step 3 as fault-free; if not, a step 12 then checks whether the temperature gradient T(t 4 ) ⁇ T(t 3 ) between times t 3 and t 4 is greater than or equal to the minimum value for the temperature drop in this time period. If so, the sensor is then classified in step 3 as fault-free; if not, a step 13 then checks whether the temperature T(t 4 ) at time t 4 is less than a temperature Tmax (t 4 ). If so, the sensor is once again classified in step 3 as fault-free; if that is once again not the case, in a step 14 the sensor is finally characterized as defective.
Abstract
Description
Claims (3)
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102004061815 | 2004-12-22 | ||
DE102004061815A DE102004061815A1 (en) | 2004-12-22 | 2004-12-22 | Method for monitoring the functionality of a temperature sensor |
DE102004061815.1 | 2004-12-22 | ||
PCT/EP2005/055484 WO2006066988A1 (en) | 2004-12-22 | 2005-10-24 | Method for monitoring the functional capacity of a temperature sensor |
Publications (2)
Publication Number | Publication Date |
---|---|
US20090129430A1 US20090129430A1 (en) | 2009-05-21 |
US7857508B2 true US7857508B2 (en) | 2010-12-28 |
Family
ID=35385640
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/793,836 Expired - Fee Related US7857508B2 (en) | 2004-12-22 | 2005-10-24 | Method for monitoring the functionality of a temperature sensor |
Country Status (5)
Country | Link |
---|---|
US (1) | US7857508B2 (en) |
EP (1) | EP1831527B1 (en) |
JP (1) | JP4436870B2 (en) |
DE (2) | DE102004061815A1 (en) |
WO (1) | WO2006066988A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100235141A1 (en) * | 2009-03-16 | 2010-09-16 | Gm Global Technology Operations, Inc. | On-board diagnostics of temperature sensors for selective catalyst reduction system |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004061815A1 (en) * | 2004-12-22 | 2006-07-06 | Robert Bosch Gmbh | Method for monitoring the functionality of a temperature sensor |
JP5573352B2 (en) * | 2010-05-17 | 2014-08-20 | いすゞ自動車株式会社 | Validity diagnosis system for urea water temperature sensor |
DE102012217787B3 (en) | 2012-09-28 | 2014-02-13 | Robert Bosch Gmbh | Method and device for diagnosing a device for determining the temperature of a component of an electrical unit |
CN113532699A (en) * | 2020-04-21 | 2021-10-22 | 北京罗克维尔斯科技有限公司 | Fault detection method and device for temperature sensor |
Citations (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4774910A (en) | 1985-10-21 | 1988-10-04 | Honda Giken Kogyo Kabushiki Kaisha | Engine cooling system |
DE4426494A1 (en) | 1994-07-27 | 1996-02-01 | Bosch Gmbh Robert | Vehicle IC engine cooling system monitoring device |
DE10120968A1 (en) | 2001-04-27 | 2002-11-21 | Audi Ag | Monitoring method for the operation of a temperature sensor used in a combustion engine with which hanging of a thermistor can be reliably detected by monitoring of temperature oscillations |
US6690016B1 (en) * | 1998-02-10 | 2004-02-10 | Philip Morris Incorporated | Process control by transient thermography |
US20040184507A1 (en) | 2003-02-20 | 2004-09-23 | Toshinori Tsukamoto | Failure diagnosing apparatus for an engine cooling water temperature sensor |
US7069141B2 (en) * | 2001-04-23 | 2006-06-27 | Siemens Aktiengesellschaft | Method for determining the oil temperature in an internal combustion engine |
US7168397B2 (en) * | 2001-07-11 | 2007-01-30 | Valeo Thermique Moteur | Control valve for cooling circuit |
US20070047616A1 (en) * | 2005-08-25 | 2007-03-01 | Honda Motor Co., Ltd. | Failure determination system and method for temperature sensors, as well as engine control unit |
US20080115487A1 (en) * | 2004-11-25 | 2008-05-22 | Toyota Jidosha Kabushiki Kaisha | Exhaust Heat Recovery System Abnormality Detection Device |
US20080253429A1 (en) * | 2004-01-07 | 2008-10-16 | Kefico Corporation | Method for Detecting Fault of Oil Temperature Sensor for Automatic Transmission |
US20080262673A1 (en) * | 2007-04-23 | 2008-10-23 | Hamama Wajdi B | Engine oil temperature diagnostic methods and systems |
US20090003405A1 (en) * | 2007-06-29 | 2009-01-01 | Todd Corbet | Sensor rationality diagnostic |
US20090090097A1 (en) * | 2007-10-09 | 2009-04-09 | Gaskins Ronald E | Method and apparatus for detecting a non-operational status of a catalyst in an engine exhaust conduit |
US20090129430A1 (en) * | 2004-12-22 | 2009-05-21 | Dirk Foerstner | Method for Monitoring the Functionality of a Temperature Sensor |
US20090168832A1 (en) * | 2008-01-02 | 2009-07-02 | Gm Global Technology Operations, Inc. | Temperature sensor diagnostics |
US20100058848A1 (en) * | 2008-09-11 | 2010-03-11 | Gm Global Technology Operations, Inc. | Engine coolant temperature estimation system |
US20100067560A1 (en) * | 2008-09-16 | 2010-03-18 | Denso Corporation | Diagnostic apparatus for vehicle cooling system |
US20100195782A1 (en) * | 2006-02-27 | 2010-08-05 | Yoshihiko Ishii | Temperature Detection Apparatus For Natural Circulation Boiling Water Reactor |
-
2004
- 2004-12-22 DE DE102004061815A patent/DE102004061815A1/en not_active Withdrawn
-
2005
- 2005-10-24 WO PCT/EP2005/055484 patent/WO2006066988A1/en active IP Right Grant
- 2005-10-24 EP EP05799443A patent/EP1831527B1/en not_active Expired - Fee Related
- 2005-10-24 US US11/793,836 patent/US7857508B2/en not_active Expired - Fee Related
- 2005-10-24 DE DE502005004596T patent/DE502005004596D1/en active Active
- 2005-10-24 JP JP2007547409A patent/JP4436870B2/en not_active Expired - Fee Related
Patent Citations (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4774910A (en) | 1985-10-21 | 1988-10-04 | Honda Giken Kogyo Kabushiki Kaisha | Engine cooling system |
DE4426494A1 (en) | 1994-07-27 | 1996-02-01 | Bosch Gmbh Robert | Vehicle IC engine cooling system monitoring device |
US6690016B1 (en) * | 1998-02-10 | 2004-02-10 | Philip Morris Incorporated | Process control by transient thermography |
US7069141B2 (en) * | 2001-04-23 | 2006-06-27 | Siemens Aktiengesellschaft | Method for determining the oil temperature in an internal combustion engine |
DE10120968A1 (en) | 2001-04-27 | 2002-11-21 | Audi Ag | Monitoring method for the operation of a temperature sensor used in a combustion engine with which hanging of a thermistor can be reliably detected by monitoring of temperature oscillations |
US7168397B2 (en) * | 2001-07-11 | 2007-01-30 | Valeo Thermique Moteur | Control valve for cooling circuit |
US20040184507A1 (en) | 2003-02-20 | 2004-09-23 | Toshinori Tsukamoto | Failure diagnosing apparatus for an engine cooling water temperature sensor |
US20080253429A1 (en) * | 2004-01-07 | 2008-10-16 | Kefico Corporation | Method for Detecting Fault of Oil Temperature Sensor for Automatic Transmission |
US20080115487A1 (en) * | 2004-11-25 | 2008-05-22 | Toyota Jidosha Kabushiki Kaisha | Exhaust Heat Recovery System Abnormality Detection Device |
US20090129430A1 (en) * | 2004-12-22 | 2009-05-21 | Dirk Foerstner | Method for Monitoring the Functionality of a Temperature Sensor |
US20070047616A1 (en) * | 2005-08-25 | 2007-03-01 | Honda Motor Co., Ltd. | Failure determination system and method for temperature sensors, as well as engine control unit |
US20100195782A1 (en) * | 2006-02-27 | 2010-08-05 | Yoshihiko Ishii | Temperature Detection Apparatus For Natural Circulation Boiling Water Reactor |
US20080262673A1 (en) * | 2007-04-23 | 2008-10-23 | Hamama Wajdi B | Engine oil temperature diagnostic methods and systems |
US20090003405A1 (en) * | 2007-06-29 | 2009-01-01 | Todd Corbet | Sensor rationality diagnostic |
US20090090097A1 (en) * | 2007-10-09 | 2009-04-09 | Gaskins Ronald E | Method and apparatus for detecting a non-operational status of a catalyst in an engine exhaust conduit |
US20090168832A1 (en) * | 2008-01-02 | 2009-07-02 | Gm Global Technology Operations, Inc. | Temperature sensor diagnostics |
US20100058848A1 (en) * | 2008-09-11 | 2010-03-11 | Gm Global Technology Operations, Inc. | Engine coolant temperature estimation system |
US20100067560A1 (en) * | 2008-09-16 | 2010-03-18 | Denso Corporation | Diagnostic apparatus for vehicle cooling system |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100235141A1 (en) * | 2009-03-16 | 2010-09-16 | Gm Global Technology Operations, Inc. | On-board diagnostics of temperature sensors for selective catalyst reduction system |
US8515710B2 (en) * | 2009-03-16 | 2013-08-20 | GM Global Technology Operations LLC | On-board diagnostics of temperature sensors for selective catalyst reduction system |
Also Published As
Publication number | Publication date |
---|---|
JP2008524506A (en) | 2008-07-10 |
EP1831527A1 (en) | 2007-09-12 |
WO2006066988A1 (en) | 2006-06-29 |
US20090129430A1 (en) | 2009-05-21 |
DE502005004596D1 (en) | 2008-08-14 |
EP1831527B1 (en) | 2008-07-02 |
DE102004061815A1 (en) | 2006-07-06 |
JP4436870B2 (en) | 2010-03-24 |
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